Upper Permian Plant Fossil Assemblage of Bijori Formation: A Case Study of Glossopteris Flora beyond the Limit of Raniganj Formation

Plant fossils collected from the Bijori Formation of Satpura Gondwana Basin are described in detail from the type locality as well as from other exposures. The assemblage is dominated by glossopterid remains with few specimens of pteridophyte of Glossopteris flora viz. Santhalea bansloiensis, Neomariopteris sp., Trizygia speciosa and 20 species of Glossopteris viz., G. angustifolia, G. searsoliensis, G. tenuifolia, G. surangei, G. kamthiensis, G. utkalensis, G. syaldiensis, G. sp. cf G. zeilleri, G. stricta, G. bosei, G. intermittens, G. stenoneura, G. gopadensis, G. wilkinsonii, G. retifera, G. conspicua, G. mohudaensis, G. browniana, G. communis, G. indica, Vertebraria indica, dispersed seeds of Cordaicarpustype and equisetalean axes with or without nodes and internodes.

Bijori bed is correlated with the Raniganj Formation of Damodar Basin but present study indicates that floristically it is distinct. Plant fossils of Raniganj are represented by large size species of Glossopteris with fair representation of arthrophytes and ferns where as, Bijori Formation contains narrow shaped small sized species of Glossopteris and shows poor record of pteridophytes. It has been observed that the assemblage of Bijori is comparable with the plant fossil assemblages of non-coaliferous beds of Kamthi and Pachhwara Formations of Mahanadi, Wardha and Rajmahal Basins which are also considered younger than Raniganj Formation. The occurrence of different types of plant fossils beyond the limit of coal-bearing Raniganj Formation in Bijori, Kamthi and Pachhwara Formations signifies the closing chapter of Permian Glossopteris flora in Peninsular India with the continuation of some forms in the lower Triassic beds.

The non- existence of Dicroidium-pinnule in present assemblage rules out its faithful association with the Triassic flora.